19x + rx = -37x + w
Add 37x on both sides
19x + rx + 37x = w
Factor out the x
x(19 + r + 37) = w
You can simplify this to:
x(56 + r) = w
Divide (56 + r) on both sides to get x by itself
x = 
Answer:
A=25
B=98
Step-by-step explanation:
You can see it as a 2-eq system.
Call A Joao's money and B Luiz's money. The sum is $123:
A + B = 123
As the half of Luiz's money + 1 is the double of Joao's money, we could represent this as:
(B/2) + 1 = 2A [this is what the last sentence says]
We can get the A value by dividing both sides by 2:
[(B/2) + 1]/2 = 2A / 2
B/4 + 1/2 = A
Then, replacing this A value on our first equation:
B/4 + 1/2 + B = 123
B/4 + 4B/4 = 123 - 1/2
(5/4)B = 122.5
Multiplying by (4/5) [or dividing by 5/4] to eliminate this 5/4:
(5/4) B * (4/5) = 122.5(4/5)
B = 98
Then we find A:
A = B/4 + 1/2 = 24.5 + 0.5 = 25
A=25
so 21 - 13, the money will be invested for 8 years.

Answer:
-8c+6
Step-by-step explanation:
2(-6c+3)+4c = -12c+6+4c = -8c+6
Eh can travel 4875 feet in 15 minutes.
Hope this helps!